FIREPROOF CONSTRUCTION OF WINDOW SHUTTER

PROBLEM TO BE SOLVED: To improve fireproof performance of a guide rail structure.SOLUTION: A guide rail 3 comprises: a first side edge 30 located closer to an external wall W; and a second side edge 31 located farther from the external wall W to face an outdoor space. A thermal expansion fireproof member 8 extending in a height direction along a part of the inner surface of the first side edge 30 is provided so as not to project toward a guide space G at ordinary temperature. The guide rail 3 is supported by a guide rail base frame 2 provided in a projecting state on the external wall W. The guide rail base frame 2 comprises: an outer side edge 20 facing an outdoor space; and an inner side edge 21 facing a space formed between a shutter curtain in a fully closed state of an opening and the external wall W. The outer side edge 20 of the guide rail base frame 2 is mounted to a base end side part of the first side edge 30 of the guide rail 3, and the inner side edge 21 of the guide rail base frame 2 is mounted to a part closer to the tip side than the base end edge of the thermal expansion fireproof member 8 of the first side edge 30 of the guide rail 3.